This document contains details of the syllabus for the subject Digital Electronics for the academic year 2011-2012 at Kings College of Engineering. It includes 5 units covering topics such as binary logic, number systems, Boolean algebra, logic gates, combinational logic, sequential circuits, memory and programmable logic. Each unit contains short answer questions and longer 16 mark questions. The questions assess students' understanding of key concepts in digital electronics and their ability to analyze, design and explain various digital components and circuits.

1. EC1201 Digital Electronics ECE
KINGS COLLEGE OF ENGINEERING
DEPARTMENT OF ELECTRONICS AND COMMUNICATION ENGINEERING
ACADEMIC YEAR 2011- 2012 / ODD SEMESTER
Subject Code: EC1201
Subject Name: Digital Electronics Year / Sem: II/III
Unit – I
PART-A (2 MARKS)
1) Define binary logic.
2) Convert (634)8 to binary
3) State the different classification of binary codes
4) Convert 0.640625 decimal numbers to its octal equivalent.
5) State the steps involved in Gray to binary conversion
6) What is meant by bit & byte?
7) List the different number systems
8) State the abbreviations of ASCII and EBCDIC code
9) What are the different types of number complements?
10) State the associative property of Boolean algebra.
11) State De Morgan's theorem.
12) Simplify the following using De Morgan's theorem [((AB)'C)'' D]'
13) What is a Karnaugh map?
14) Find the minterms & maxterms of the logical expression.
15) What are called don’t care conditions?
PART-B (16 MARKS)
1. Reduce the expression F = Σ m(1,,6,12,13,14) + d(2,4) is SOP and POS forms. (16)
2. Determine the prime implicants of the function
F (W,X,Y,Z) = Σ (1,4,6,7,8,9,10,11,15) (16)
3. Simplify the Boolean function using K-map.
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2. EC1201 Digital Electronics ECE
F(A,B,C,D,E) = (0,2,4,6,9,13,21,23,25,29,31) (16)
4. Reduce the following function using K-map technique
f(A,B,C,D)=π M (0,2,3,8,9,12,13,15) (16)
5. Reduce the following function using k-map technique
f(A,B,C,D)= π M(0,3,4,7,8,10,12,14)+d(2,6) (16)
6. Implement F=((A+B).(C+D))’ + A using NAND gates and NOR gates only. (16)
Unit – II
PART-A (2 MARKS)
1. What are Logic gates?
2. What are the basic digital logic gates?
3. Which gates are called as the universal gates? What are its advantages?
4. Classify the logic family by operation
5. State the classifications of FET devices.
6. Mention the classification of saturated bipolar logic families.
7. Mention the different IC packages.
8. Mention the important characteristics of digital IC’s.
9. Define fan-out & fan-in.
10. Define power dissipation
11. What is propagation delay?
12. Define noise margin
13. What is Operating temperature?
14. What are the types of TTL logic?
15. State the advantages and disadvantages of TTL
PART-B (16 MARKS)
1. Explain TTL with neat diagrams. (16)
2. Discuss all the characteristics of digital IC’s. (16)
3. Explain in detail about Schottky TTL. (16)
4. Explain with neat diagrams ECL. (16)
5. Explain with necessary diagrams MOS (16)
6. Explain in detail about interfacing CMOS and TTL device (16)
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3. EC1201 Digital Electronics ECE
7. Give the comparison between TTL and CMOS families (16)
Unit III
PART-A (2 MARKS)
1. Define combinational logic
2. Explain the design procedure for combinational circuits
3. Define decoder & binary decoder
4. Define Encoder & priority Encoder
5. Define multiplexer
6. What do you mean by comparator?
7. Define carry propagation delay
8. Write the truth table and logic circuit for half adder
9. Explain the condition for parallel adder/subtractor
10. Draw the logic circuit of full adder using half adder
11. Explain the carry generate and carry propagate
12. Define parity generator
13. Draw the block diagram of multiplexers
14. Define parity checker
15. Explain even and odd parity
PART-B (16 MARKS)
1. Explain the working of BCD Ripple Counter with the help of state diagram and logic diagram.
(16)
2. Design a logic circuit to convert the BCD code to Excess – 3 codes. (16)
3. Explain the carry lookahead adder (16)
4. Explain the BCD adder with examples (16)
5. Explain the any two code converters (16)
6. Explain in detail about (SISO, PISO and PIPO) shift register. (16)
Unit IV
PART-A (2 MARKS)
1. What are the classifications of sequential circuits?
2. Define Flip flop.
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4. EC1201 Digital Electronics ECE
3. What are the different types of flip-flop?
4. What is the operation of JK flip-flop?
5. Define race around condition.
6. What is edge-triggered flip-flop?
7. What is a master-slave flip-flop?
8. Define rise time & fall time.
9. Define skew and clock skew.
10. Define setup time.
11. Define hold time.
12. Define register.
13. Define shift registers.
14. What are the different types of shift type?
15. Define synchronous & asynchronous sequential circuit
PART-B (16 MARKS)
1. Explain the analysis of clocked sequential circuits with examples (16)
2. Design an asynchronous sequential circuit with 2 inputs T and C. The output attains a value of
1 when T = 1 & C moves from 1 to 0. Otherwise the output is 0. (16)
3. A asynchronous sequential machine has one input line where 0’s and 1’s are being incident.
The machine has to produce a output of 1 only when exactly two 0’s are followed by a ‘1’ or
exactly two 1’s are followed by a ‘0’.Using any state assignment and JK flipflop, synthesize the
machine (16)
4. Design an asynchronous sequential circuit with 2 inputs X and Y and with one output Z
Wherever Y is 1, input X is transferred to Z .When Y is 0; the output does not change for any
change in X.Use SR latch for implementation of the circuit (16)
5. Develop the state diagram and primitive flow table for a logic system that has 2 inputs,x and y
and an output z.And reduce primitive flow table. The behavior of the circuit is stated as follows.
Initially x=y=0. Whenever x=1 and y = 0 then z=1, whenever x = 0 and y = 1 then z = 0.When
x=y=0 or x=y=1 no change in z ot remains in the previous state. The logic system has edge
triggered inputs with out having a clock .the logic system changes state on the rising edges of the
2 inputs. Static input values are not to have any effect in changing the Z output (16)
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6. Design an asynchronous sequential circuit with two inputs X and Y and with one output Z.
Whenever Y is 1, input X is transferred to Z.When Y is 0,the output does not change for any
change in X. (16)
7. Obtain the primitive flow table for an asynchronous circuit that has two inputs x,y and one
output Z. An output z =1 is to occur only during the input state xy = 01 and then if the only if the
input state xy =01 is preceded by the input sequence. (16)
8. A pulse mode asynchronous machine has two inputs. It produces an output whenever two
consecutive pulses occur on one input line only .The output remains at ‘1’ until a pulse has
occurred on the other input line. Draw the state table for the machine. (16)
9. Construct the state diagram and primitive flow table for an asynchronous network that has two
inputs and one output. The input sequence X1X2 = 00,01,11 causes the output to become 1.The
next input change then causes the output to return to 0.No other inputs will produce a 1 output.
(16)
10. Draw the state diagram and characteristics equation of T FF, D FF and JK FF
State diagram (16)
11. Design and explain the working of a synchronous mod – 7 counter (16)
12.Design a synchronous counter for 4->6->7->3->1->-----4… avoid lockout condition, use JK
type design (16)
13. Design and explain the working of a synchronous mod –3 counter (16)
14.Design a 2 bit up/ down counter using T flip flops. Implement using synchronous design. (16)
Unit V
PART-A (2 MARKS)
1. What are the types of ROM?
2. Explain PROM.
3. Explain EPROM.
4. Explain EEPROM.
5. What is programmable logic array? How it differs from ROM?
6. Give the classification of PLDs.
7. Define PLA
8. Define PAL
9. Why was PAL developed ?
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10. Define GAL
11. What is CPLD ?
12. What is Read and Write operation?
13. Define Static RAM and dynamic RAM
14. Define Cache memory
15. Give the feature of flash memory.
PART – B (16 MARKS)
1. Explain in detail about PLA with a specific example. (16)
2. Explain with neat diagrams RAM architecture. (16)
3. Explain in detail about PLA and PAL. (16)
4. Explain with neat diagrams a ROM architecture. (16)
5. Explain in detail about RAM organization (16)
6. Explain the static RAM and dynamic RAM. (16)
7. Explain and draw the memory cycles and timing waveforms (16)
8. Details briefly about Field programmable gate arrays (16)
9. Explain in detail about memory decoding (16)
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